But we rarely stop to consider the crucial lifeline that connects
us to this new-age lifestyle — the hundreds of millions of Wi-Fi
networks and cellphone towers across the globe, which make it all
possible.

Now, you can see what this lifeline
looks like in some of the largest cities in the world, thanks
to the producers at Mapbox
and Skyhook. Each
yellow dot in the map below of the eastern US is a single Wi-Fi
signal:

Fischer says his map is the most precise one ever made that
features global Wi-Fi interconnectivity.

"It's these Wi-Fi points that are the key for making positioning
on your phone super accurate," Lindsay Young, who is another
expert at Mapbox, told Business Insider in an email.
"Everyone always thinks GPS is what puts the blue dot on your map
-- but GPS is only accurate within 10 meters and phones don't
have super powerful GPS antennas."

When you zoom in on a massive city like Manhattan, you get a
breathtaking site of electronic activity:

"If you zoom out from the dense coverage of Manhattan, you can
see neighborhoods full of yellow, all mapped within the last six
months, where many people are constantly passing by with cell
phones," Fischer wrote on his blog for Mapbox.
"The result is a snapshot of how people are moving through the
city each day."

Some cities are displayed in different colors. For example,
Seoul, in South Korea has more pink and purple than yellow. The
different colored dots "show the diverse ecosystems of Wi-Fi and
cell towers," Fischer told Business Insider. Here's Seoul:

These maps looks remarkably similar to photos snapped from space
of city lights. But instead of physical light, we're seeing the
tremendous activity of electronics across the globe. Here you can
see the Wi-Fi hot spots of England, France, and Belgium as they
illuminate the map: